...the Random Proximity Stone.
The wishing stone that Jon's grandfather sent him had existed for several centuries before Jon's grandfather first encountered it. And in that time, several other versions of the stone had been created, each with their own variations on the concept that set it apart from the 'regular' wishing stone (also known as the Jewel of Cusco to those who researched magical items). Many of these alternate wishing stones had fallen into the hands of people who were seeking the original wishing stone. Among those other wishing stones were the Proximity Stone and the Random Stone.
The Proximity Stone worked just like the regular wishing stone, except that one didn't have to be holding the stone for their wishes to be granted. As long as the person was within 20 feet of the stone when they made their wish, their wish would be granted whether they knew the stone was there or not.
The Random Stone looked nearly the same as the regular wishing stone, but it wasn't. It was the Random Stone. And because of the small crack running through it, the wishes made with it wouldn't necessarily be granted to the wisher. The stone would pick out someone within 50 feet of the one who made the wish and grant it to him or her instead (as if they were the ones who made the wish). It was completely random as to whom the stone would pick. And as with the original stone, only the wisher and those who heard the wish made would notice the changes in reality.
At some point in history, someone, for reasons known to few other than them, decided to create a wishing stone that was a combination of the above two stones. This stone is known as the Random Proximity Stone.
So if someone were to make a wish on this stone, it wouldn't be granted necessarily to the wisher. The stone would, as described above, pick someone within 50 feet of the wish and grant it to him or her instead (as if they were the one who made the wish). It was completely random who the stone would pick. Combine that with the Proximity Stone's not even needing someone to be holding the stone for the wishes to be granted, and you had a recipe for chaos.
Jon would awake the next morning, not knowing that his stone had been switched and the stone next to his bed was the Random Proximity Stone.
